The West Fjords are the oldest part of this young land, being 14-16 million years old. As a result of extensive glaciation over much of this period, most, but not all, of the mountains are flat-topped with steep U-shaped valleys. Many of these contain deep fjords. Because of this terrain, the roads of the West Fjords are among the most difficult (not to say worst!) in the whole country with more than their fair share of steep climbing switchbacks on gravel roads. Many are only open a few months of the year during summer. This contributes to its isolation and fewer tourists venture here than any other part of the island. The scenery here, like that in the East Fjords, is a little more mature looking than that in the south or centre of Iceland where vulcanism is more recent.